单词：troughs
音标：[trɔ:fs] ；
n. 低谷( trough的复数形式 ); 波谷; （喂动物的）食槽; 檐槽
n. a narrow depression (as in the earth or between ocean waves or in the ocean bed)
n. a channel along the eaves or on the roof; collects and carries away rainwater
n. a concave shape with an open top
n. a channel along the eaves or on the roof; collects and carries away rainwater
n. a concave shape with an open top